package nova-common 1:2014.1.3-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[fengnan-man]

when update from ubuntu 12.04 to 14.04

ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: nova-common 1:2014.1.3-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.5
Architecture: amd64
Date: Thu Oct 23 21:11:13 2014
DuplicateSignature: package:nova-common:1:2014.1.3-0ubuntu1:subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
PackageArchitecture: all
SourcePackage: nova
Title: package nova-common 1:2014.1.3-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to trusty on 2014-10-23 (0 days ago)
mtime.conffile..etc.nova.api.paste.ini: 2014-10-16T09:43:26.760223
mtime.conffile..etc.nova.nova.conf: 2014-10-23T21:11:12.175551

[Chuck Short (zulcss)]

Looks like bad configuration file:

Configuration file '/etc/nova/nova.conf'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ? Your options are:
    Y or I : install the package maintainer's version
    N or O : keep your currently-installed version
      D : show the differences between the versions
      Z : start a shell to examine the situation
 The default action is to keep your current version.
*** nova.conf (Y/I/N/O/D/Z) [default=N] ?
Installing new version of config file /etc/logrotate.d/nova-manage ...
Traceback (most recent call last):
  File "/usr/bin/nova-manage", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/dist-packages/nova/cmd/manage.py", line 1323, in main
    config.parse_args(sys.argv)
  File "/usr/lib/python2.7/dist-packages/nova/config.py", line 37, in parse_args
    default_config_files=default_config_files)
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 1632, in __call__
    else sys.argv[1:])
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2133, in _parse_cli_opts
    return self._parse_config_files()
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 2147, in _parse_config_files
    ConfigParser._parse_file(config_file, namespace)
  File "/usr/lib/python2.7/dist-packages/oslo/config/cfg.py", line 1252, in _parse_file
    raise ConfigFileParseError(pe.filename, str(pe))
oslo.config.cfg.ConfigFileParseError: Failed to parse /etc/nova/nova.conf: at /etc/nova/nova.conf:2, Section must be started before assignment: None
dpkg: error processing package nova-common (--configure):